The invention relates in general to sensors and, more particularly, to a hand held, self-contained, automatic, low power and rapid sensor platform for detecting a plurality of analytes.
While the invention can be used to detect a wide variety of analytes, the initial embodiment was developed for use against aflatoxin which is formed from a fungus commonly found in many grain products and peanuts. Studies have proven that ingesting aflatoxin can cause serious health problems. The FDA is aware of this health risk and has set tolerance levels for aflatoxin for United States products such as flour and milk.
However, high levels of aflatoxin do still exist in food in remote areas and foreign countries, where it is also used in weaponry. It is these unacceptable levels in food and the potential use in weapons that have prompted investigations into a portable sensor for aflatoxin and, by extension, to other analytes of interest as well.
There currently exist two different measurement techniques for aflatoxin levels. The easiest and most portable method currently available uses a "wet chemistry" approach. This method uses a paper that changes color when immersed in a minimum concentration of aflatoxin. Currently available test papers are for minimum levels of 5 parts per billion (ppb) and 20 ppb.
The second, less portable method of measuring aflatoxin levels uses affinity chromatography and a series of manual fluid wash and rinse cycles that effectively selectively remove the aflatoxin from the initial sample solution. The aflatoxin, contained in the final rinse (elution) fluid, may then be placed in a fluorometer where its fluorescence can be measured and correlated to the level of aflatoxin in the initial sample.
Despite the existence of the above techniques, a need remains for a hand held, self-contained, automatic sensor with increased sensitivity to replace the less sensitive "wet chemistry" method and the large, cumbersome, chemical laboratory analysis systems. The new sensor should be viable for use not only against aflatoxin but against other analytes of agricultural, public health and defense interest as well. A modular design permitting the rapid substitution of different reagents and/or affinity columns to permit detection of various analytes with the same sensor would provide even greater benefits.